NCAA investigating bracket leak

Entire bracket posted early on Twitter

The NCAA is initiating an investigation after the full bracket for the men's basketball tournament was leaked online early into CBS's Sunday selection show.

"We go to great lengths to prevent the tournament field from being revealed early and the NCAA took its usual measures to prevent this from happening," the NCAA said in a statement Sunday night. "Unfortunately, and regrettably, the bracket was revealed prior to our broadcast partners having the opportunity to finish unveiling it. We take this matter seriously and we are looking into it."

The selection show, which started at 5:30 p.m. ET, was extended to two hours this year. But the entire bracket was posted by an anonymous Twitter account by 6:20 p.m. After first being received with skepticism, it proved to be 100 percent accurate.

The original posting of the bracket and the entire account that sent it out disappeared from Twitter late Sunday evening.